Hydraulically operated bottom closure for a straining tank



Feb. 25, 1969 H. E. HICKS ET AL 3,429,782

HYDRAULICALLY OPERATED BOTTOM CLO SURE FOR A STRAINING TANK Filed Oct. 21, 1965 Sheet of 4 1 f I g M l I ll i i o /9 .w I 5K 1 Q2 I Z7 on 5 H Fl G I v l? 2s 29 .9 5 Z a: z74 Z8 Z Z6 fjffilii'i 11111:;

, M,M;UM

Feb. 25, 1969 H. E. HICKS ETAL 3,429,732

HYDRAULICALLY OPERATED BOTTOM CLOSURE FOR A STRAINING TANK- Sheet Filed Oct. 21. 1965 m Fl (3,6

Ahrarniers;

m 4 fa mww FM m M MM w HEM m L X z Feb. 25, 1969 H. E. HICKS ET 3,429,782

HYDHAULICALLY OPERATED BOTTOM CLOSURE FOR A STRAINING TANK Sheet 3 of 4 1 I I l l I I I I I I m lllllllll-IIF Filed Oct. 21. 1965 Feb. 25, 1969 H. E. HICKS ET AL 3,429,782

HYDRAULICALLY OPERATED BOTTOM CLOSURE FOR A STRAINING TANK Filed Oct. 21. 1965 Sheet 4 or 4 SGLE/VOIJJ 00524750 I 4 1m, new: 15 40701 5949750 I l I I C 3 f i 52 53 {Wye/V7025. awwwzmc/(s H G 9 i I 5 r aim 422 57%.

0/4. .zesaemne 55 .3 I faw f United States Patent 3,429,782 HYDRAULICALLY OPERATED BOTTOM CLOSURE FOR A STRAINING TANK 7 Harold E. Hicks, Kirkwood, and Bernard F. Pohl, Alfton,

Mo., assignors to Nooter Corporation, St. Louis, Mo.,

a corporation of Missouri Filed Oct. 21, 1965, Ser. No. 499,470

US. Cl. 195135 14 Claims Int. Cl. F17c 1/00 ABSTRACT OF THE DISCLOSURE A bottom closure for a straining tank, said bottom closure being maintained in closed position by hydraulic pressure within a cylinder. On the bottom closure is mounted a guide member having a front edge extending downwardly and rearwardly. To the guide member is fixedly attached a flexible means which actuates the bottom closure to its closed position when pressure is applied by the hydraulic cylinder.

This invention relates to a bottom closure for a tank, and more particularly, to a gate assembly for use with straining tanks of the kind shown in US. Patents Nos. 2,916,421 and 2,936,236.

At present, the outlet valves or spent grain gates are small and are mechanically operated. This sometimes results in an uneven flow of spent grain from the straining tank, thereby causing some of the spent grain not to flow or to clog the tank. This then requires manual labor to free the tank of spent grain.

One of the principal objects of the present invention is to provide a novel bottom closure means for a straining tank. Another object is to provide a hydraulic means for opening said closure, said closure design and said hydraulic means permitting a plurality of large doors to be operated simultaneously so that the wet spent grain from the large straining tank moves downwardly uniformly without clogging to free the entire straining tank from spent grain. Another object is to provide large bottom doors which are leakproof and hold liquid above them. Another object is to provide a hydraulic system which can be operated by one man for opening a plurality of large doors rapidly and simultaneously to effect rapid and complete removal of all spent grain.

Another object is to provide a system for opening a plurality of doors quickly and simultaneously thereby allowing all of the contents supported by said doors to be removed simultaneously. A further object is to provide a construction for such a system which need not be made from expensively machined and delicately fit parts.

These and other objects and advantages will become apparent hereinafter.

The invention is embodied in a bottom closure for a straining tank, said bottom closure being maintained in closed position by hydraulic pressure within a cylinder exerting its force against a piston having a piston rod connected thereto with a flexible connection to means on said bottom closure for allowing the hydraulic cylinder to exert its force in the most efficient direction. The invention is also embodied in a method of removing mash from a straining tank.

This invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed. In the accompanying drawings which form part of this specification and wherein like numerals andsymbols refer to like parts wherever they occur:

FIG. 1 is a side elevational view showing a bottom closure embodying the present invention,

FIG. 2 is a fragmentary view similar to FIG. 1 but "ice showing a side view of the bottom closure in its open position, the dotted lines representing the closed position,

FIG. 3 is a front view, partially broken, of the bottom portion of a straining tank having a plurality of bottom closures,

FIG. 4 is a bottom view of the door itself,

FIG. 5 is an end view of the door itself with the chain guides thereon,

FIG. 6 is a bottom view of the doors,

FIG. 7 is an enlarged sectional view along the line 77 of FIG. 6 showing the seal clamped to the bottom flange of the straining tank by retaining means,

FIG. 8 is an enlarged section view along the line 88 of FIG. 6, and

FIG. 9 is a schematic flow diagram of the hydraulic and electric system for operating the plurality of bottom doors.

Referring now to the drawings in detail, it will be seen that the invention is embodied in a bottom closure 1 for a straining tank T or other kind of vessel having flowable material therein. The straining tank T is large, for example, about 24 feet long, 10 feet wide, and 11 feet tall. The straining tank T has an upper head or cover 2, a tubular or enclosing wall 3 which may be curved or rectangular, and a sloping bottom portion 4 with a large horizontal opening 5 at the bottom thereof which is closed by the bottom closure 1. Thus, several feet of grain and liquid material in the straining tank T rest directly upon and above the bottom closure 1 and are supported thereby. The bottom portion 4 has a flange 6 surrounding the opening 5. 7

Suitable piping, supports, inlets and outlets, man openings, and controls are operatively connected to the straining tank T for its proper operation, as more fully described in U.S. Patents Nos. 2,916,421 and 2,936,236. The present invention relates to the bottom closure 1 which closes the opening 5 in the sloping bottom portion 4, seals said opening 5, supports the grain and liquid thereabove, and opens to allow the spent grain to fall from the straining tank T.

The bottom closure 1 comprises a plurality of doors 7, each relatively large in size. Each door 7 has a rear edge 8 hinged at the inclined or sloping bottom 4 on one or more hinges 9 connected to the flange 6 and extends horizontally across the opening 5 in its closed position. Each door 7 has a thickness for strength. Each door 7 has a front edge 10 parallel to the rear edge 8 and opposite to the hinge 9. Each door 7 has a pair of spaced guide members 11 therebelow, which are segments of circles whose center is said hinge 9. The guide members 11 have curved front surfaces 12, which are arcs of a circle, and rear inclined surfaces 13 extending to said hinges 9. To the lower portions 13 of said members 11 are secured straps or chains 14, or other flexible supporting means. These chains 14 extend upwardly along the front surfaces 12 of the members 11 and are secured to rods 15 in pressure cylinders 16 which are angularly supported outside of said sloping bottom 4 in substantial parallel relation thereto on a bracket 17 by a pivotal connection 18. The pressure cylinders 16 are shown as hydraulic cylinders, but air cylinders or a combination of air and hydraulic cylinders may be used, if desired. As used herein, the term hydraulic cylinder shall mean either hydraulic cylinders or air cylinders or a combination thereof.

Suitable hoses 19 and 20 are attached to each of said hydraulic cylinders 16 for allowing pressure fluid to fiow into one end or the other end of said hydraulic cylinders 16. The hydraulic cylinders 16 may be of conventional type which have a piston and a piston rod 15 therein with suitable seals to prevent leakage. The end of the 3 piston rod has a bracket 21 to which is attached the chain 14.

A lower housing 22 is positioned under the sloping bottom 4 and connected to the flange 6. The lower housing 22 has inclined tubular members 23 thereon with expandable or flexible bellows shields 24 which may be made from rubber or plastic, connecting the ends of the cylinders 16 with the tubular members 23. The bellows shields prevent spent grain and water from splashing out on the floor. Beneath said tubular members 23 in the walls 25 are positioned removable doors 26 for inspection and cleaning. The opposite side of the lower housing 22 is provided with a sloping wall 27 having a vertical lower portion 27a. The sloping wall 27 has access and inspection doors 29 therein and accommodates the spaced guide members 11 attached to the doors 7 when the latter are in their open or downward position, as shown in FIG. 2. FIG. 2 also shows that the spaced guide members 11 are arcs of circles whose centers are the hinges 9 for the bottom closures 1. The walls 25 and 27 are provided with nozzles 28 for spraying water into the lower housing 22 to clean it and the doors 1.

The individual bottom closures 1 are shown in FIG. 6, which is broken away at the left to show the downwardly facing seals 30 on the flange 6 which prevent leakage. The seal or tadpole gasket 30 is best shown in FIG. 7 and has a circular sealing portion 31 with a laterally extending flange 32, said flange 32 having holes 33 therein for receiving bolts 34 which extend through a retaining member 35 which frames the opening 5. The circular portion 31 of the seal 30 contacts the inner surface 36 of the retaining member 35. The edge of the upper surface of the door 7 is adapted to contact the seal 30.

The gasket 30 is continuous around each opening, preferably with its free ends vulcanized together, as at 37. The gasket 30 is provided with the flange 32 along its straight portions only, there being no flange 32 at the corners 38 so as to permit the gasket 30 to bend around the corners 38 more easily. Each corner 38 is provided with a back-up or curved retainer 39, as best shown in FIG. 8, which is connected to the flange 6 by the corner bolts 34. The size, shape, rigidity of material, and fastening and back-up arrangement described provides a gasket or seal 30 which prevents leakage along the straight portions and at the corner portions as well.

FIG. 9 shows a diagrammatic view of the circuit for causing all hydraulic cylinders 16 to allow the individual bottom doors 7 to open simultaneously. This is important for proper and complete removal of the spent grain from the straining tank T. The hoses 19 attached to the lower or piston rod end of each pair of cylinders 16 for each door 7 are connected to a pressure compensated control valve 40 which makes certain that the oil is released from the cylinder 16 for each door 7 at the same rate, thereby insuring simultaneous opening of the doors 7. These valves 40 regulate only when the doors 7 are opening. Lines 41 from said control valves 40 lead to a line 42 having a pressure switch 43, an accumulator 44, a maximum pressure gauge 45, and a pilot operated check valve 46 therein. A line 47 leads from said check valve 46 to a solenoid operated, two position four-way valve 48, with an oil filter 49 connected therein. The hydraulic system S is provided with an electric motor 50, a variable volume pump 51, a pressure compensator 52, a gauge 53, and a line 54 leading therefrom to the four-way valve 48 and to tubes 54 leading to the individual hoses 20 connected to the top of the hydraulic cylinders 16. The pump 51 is connected to a suitable oil reservoir 55. The purpose of the system S'wit'h the pilot operated check valve 46 and other parts therein is to make certain that the breakdown of the electric motor 50 or the loss of pressure due to oil leakage or any other reason will not allow the doors 7 to open until the operator presses the proper switch. The doors 7 are maintained n clo position by ydraulic means at all times and it is important to provide a system S which prevent accidental or premature opening of the doors 7 should the system break down, since such would result in the loss of a portion or all of the valuable contents of the straining tank T.

In operation, the normal operating position of closure door 7 is best shown in FIG. 1. In this position, the bottom closure 1 closes the opening 5 and is maintained in its closed position by hydraulic means. The hydraulic means comprises fluid pressure exerted on the lower surface of pistons in the hydraulic cylinders 16, thereby forcing the pistons to their upper positions so that the piston rods 15 are retracted into the hydraulic cylinders 16 and pull the chains 14 mounted on the spaced guide members 11 upwardly to maintain the bottom closure 1 in its closed or horizontal position with the seal 30 preventing leakage. In this position, grain and water or mash may be introduced into the straining tank T to the desired height of several feet so that great weight is placed upon the bottom closure 1. Water is introduced through the plurality of pipes within the tank to extract the soluble matter from the grain to form wort. This water further increases the height of the material within the straining tank and adds weight which bears on the bottom closure 1. After suflicient water has been introduced and the wort has been removed so that the grains become spent, the grains and the water which remain must then be removed from the straining tank T. This material tends to stick to the pipes and interior walls of the straining tank, so it becomes important to have a large bottom closure 1 which can be opened quickly and all at once.

The circuit or diagrammatic view for causing all of'the hydraulic cylinders 16 to open the individual doors 7 simultaneously and synchronously is best shown in FIG. 9. Upon operation of a switch which energizes solenoid A of 4-way valve 48, pressure fluid supplied by the pump 51is forced to the cap end of all hydraulic cylinders, forcing the pistons downward. Flow control valves 40, all three of which have been adjusted for equal flow, permit only the correct amount of pressure fluid to flow out of the rod end of the hydraulic cylinders regardless of any variation in pressure of the fluid. Thus, the piston rods of all cylinders advance outwardly from the cylinders simultaneously and synchronously. The bottom closure doors 7 open by the force of their own weight and the weight of the contents of the vessel, but are constrained by the chains 14 so that the rate of opening is determined by the rate of advance of the cylinder rods 15. Any difference in weight of material on the doors causing greater opening force on one door than another will have no effect on the rate of opening of the doors, since the flow control valves 40 are pressure compensated and their rate of flow will remain constant regardless of differences in fluid pressures. Thus, the doors fall in synchronous relationship until they reach full open position as shown in FIG. 2.

When all doors 7 open simultaneously, the material falls completely and uniformly from the straining tank T. The few grains which remain can be washed out with a hose. The hosing is a normal operation even if no grains remain, since the equipment is cleaned between each brew. If the doors do not open simultaneously and in synchronism, that is, at the same rate of speed, the grains tend to stick to one another and accumulate in certain portions of the tank, notwithstanding the fact that there is an inclined bottom 4 and numerous doors 7. This is due to the nature of the spent grains, which have a tendency to become sticky due to coagulated protein and other products which are formed during the lautering stage of the brewing process.

When all spent grain and other material have been removed from the straining tank and after the straining tank has been cleaned the bottom closure 1 may be closed so that the straining tank may receive another batch of material. The bottom closure 1 is closed by pressing a button to energize solenoid B of 4-way valve 48 which causes the electric motors 50 to pump hydraulic fluid into the underside of the cylinders 16 through the hoses 19 to force the pistons upwardly thereby pulling the chains 14 upwardly so that the doors 7 move from the open position shown in FIG. 2 to their closed position shown in FIG. 1. It will be noted that the chains 14 always exert a force substantially tangentially to the circle or spaced guide members 11 whose centers are the hinges 9. This more fully utilizes all of the pulling power exerted by the hydraulic cylinders 16. The curved front portions 12 of the guides 11 cause the doors 7 to close with a constant velocity. The hydraulic cylinders 16 are pivotally mounted to accommodate any slight deviation from a true pulling at right angles to a line between the hinge 9 and the point where the chains 14 last touch the guide members. When the piston is in its upper position, the bottom closure 1 is closed with the seal 30 pressed tightly against the upper surface of the doors 7 surrounding the bottom opening 5. Thus, the bottom closure 1 is maintained in its closed position by means of constant hydraulic pressure exerted by the hydraulic cylinders 16 which exert an upward force to maintain the individual doors 7 in closed sealed relation.

The four-way valve 48 has a spool with a detent so that it will not shift its position in the event of power failure. The pump 51 is a variable volume pressure compensated type of pump which will automatically cut back its pumping rate to maintain the pressure desired after the pistons in the cylinders are in position. This rate is determined by the flow necessary to take care of slippage due to leakage in the pump 51 itself, the four-way valve 48, and the packing of the piston and piston rod 15 in the cylinders 16 or in other seals in the system. The pump 51 runs continuously without creating heat in the oil.

In the event of power failure, and in order to prevent loss of the contents of the vessel, the pilot operated check valve 46 is used to prevent pressure from backing out through the pump 51 or four-way valve 48. Pressure in the opposite cylinder port side will open the pilot operated check valve 46 to reposition the pistons in the cylinders 16 for opening the bottom closures 1. The accumulator 44 is preferred as a further safeguard against leakage of the bottom closure 1 due to any power failure. The accumulator 44 maintains pressure against leakage which may occur in the piston seals or other portions of the system after wear due to use. A pressure switch 43 closes a contact to'sound an alarm, which may be a light and/or a horn, in the event of large leakage encountered simultaneously with a power failure causing the pressure to fall below safe limits.

The hydraulic system is running at all times in order to maintain the doors 7 in their closed position. It is important to open all doors simultaneously and in synchronism to obtain the most eflicient removal of grain from the tank T. This system would permit the use of a single door 7 regardless of the length of the tank T, which door could be operated by two or more hydraulic cylinders 16. However, such a large door would be diflicult to install, service, and remove, should that become necessary. Accordingly, a plurality of smaller doors 7 is used. But these doors 7 are quite large in comparison with the manually operated gate valves previously used.

In actual practice, the doors 7 may be about 3 feet wide and 7 feet long. These doors are sufficiently heavy to fall of their own weight when the hydraulic pressure is released. The present arrangement requires little maintenance and few parts which have to be machined to small tolerances and individually fit by hand by workmen on each individual job.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. A bottom closure for a straining tank for processing grain, said straining tank having .a large bottom opening, said bottom closure comprising a door, guide means rigidly mounted on the door having a front edge extending downwardly and rearwardly, a pressure cylinder 0n the tank, flexible elongated means connecting said guide means and said pressure cylinder and being oriented so that when a force is applied thereto by the pressure cylinder the door will be urged to its closed position, said door being maintained in closed position by the force of fluid pressure in said pressure cylinder.

2. A bottom closure for a straining tank for processing grain and having a large bottom opening, said closure including a movable door adapted to close and seal said opening, said door having a hinge along its rear edge and having a free front edge, said door having at least two spaced guide members secured thereto and projecting therebelow, said members having a front edge extending downwardly and rearwardly, flexible means secured to each of said members and adapted to contact and extend upwardly along said front edge, a pressure cylinder pivotally mounted in the same vertical plane as each of said members, said pressure cylinder having a piston rod therein, said piston rod being connected to said flexible means for applying a force thereto, said flexible means being oriented such that when a force is applied thereto b the pressure cylinder the force exerted in the guide member by the flexible means will be directed in a direction which tends to urge the door to its closed position.

3. In a straining tank for use in processing grain and having a sloping lower portion with a large bottom opening, the improvement in providing said tank with a hinged door for closing said bottom opening, guide means secured to said door and projecting therebelow, said guide means having a front edge extending downward and rearwardly from said opening, flexible means secured to said guide means and adapted to contact and extend upwardly along said front edge of said guide means, a fluid pressure cylinder connected to the upwardly extending portion of said flexible element, whereby said hinged door will be maintained in closed position by the fluid pressure cylinder, the door being free to fall by gravity to an open position upon release of said fluid pressure means.

4. A bottom closure according to claim 1 wherein said straining tank is provided with a plurality of doors each operated by a different pressure cylinder through guide means and flexible elements, and control means for reducing the pressure in the pressure cylinders so that the doors are opened by the force of gravity, said control means causing the doors to open Simultaneously and at substantially the same speed.

5. A bottom closure according to claim 1 wherein the door is hingedly connected with respect to the tank adjacent to one side of the opening, wherein the guide means has a curved surface extending outwardly from the door at a location remote from the hinged mount of the door and curving in substantially the same direction as the arc described by that edge of the door located opposite the hinge as the door moves between its open and closed positions, and wherein the flexible element extends along and conforms to the curvature of the curved surface as the door moves to its open position.

6. In a straining tank for processing grain as set forth in claim 1 and having a sloping lower portion with a large bottom opening, the improvement in providing said tank with a movable door for closing said bottom opening, said door being hydraulically operated by a hydraulic system, said system comprising a plurality of hydraulic cylinders connected to said door, 4-way valve hydraulic connections between the ends of said hydraulic cylinders and the 4-way valve, said hydraulic connections having pressure compensating devices therein to make certain that all doors open synchronously,

and a pump for maintaining pressure in said hydraulic cylinders to maintain said door in its closed position.

7. The improvement set forth in claim 6 wherein said hydraulic system is provided with an alarm to notify the operator in case of loss of pressure in said system.

8. The bottom closure set forth in claim 1 wherein said door is adapted to open by the force of gravity when the fluid pressure in the cylinder is released.

9. The bottom closure set forth in claim 1 wherein said door is adapted to open under control of said pressure cylinder when the fluid pressure in said cylinder is released.

10. The bottom closure set forth in claim 2 wherein said doors are maintained in their closed and sealed position solely by hydraulic pressure in the cylinder.

11. The bottom closure set forth in claim 2 wherein said large bottom opening has a flange therearound, said flange having a seal thereon adapted to seal the door against leakage when said door is in its closed position.

12. The bottom closure set forth in claim 11 wherein said seal on said flange has a sealing portion of circular cross-section with a seal flange extending tangentially therefrom, said seal flange being secured between said flange and a retaining member.

13. A bottom closure for a straining tank for processing grain having downwardly converging walls which downwardly terminate adjacent to a bottom opening in the tank, said bottom closure comprising a door hingedly secured with respect to the tank and adapted to swing from a closed position, wherein it engages the tank in surrounding sealing relation to the opening, to open positions wherein the door is presented away from the opening so that the contents of the tank can escape, a guide members rigidly mounted on the door and extending downwardly and and rearwardly from the opening, at least one fluid operated cylinder mounted on one of the converging walls of the tank in upwardly spaced relation to the door, said cylinder having a piston and a piston rod therein, a flexible elongated element interconnecting the guide member and the piston rod of the cylinder so that when the cylinder piston is retracted the door will be urged toward its closed position, the line of action for the cylinder being substantially along that portion of the flexible element located intermediate the piston rod and the guide member, and a fluid system for continually maintaining the fluid in the cylinder under pressure exceeding that required to close the door so that the piston is continually urged away from the door whereby a continuing closure force is maintained on the door.

14. A bottom closure according to claim 13 wherein the cylinder is pivotally mounted on the tank.

References Cited UNITED STATES PATENTS 719,052 1/1903 Selg 195-143 732,348 6/1903 Harrison -240 3,097,711 7/1963 Clark 222-504 3,160,491 2/1965 Darlington et al. 105-240 LIONEL W. SHAPIRO, Primary Examiner.

NORMAN ROSKIN, Assistant Examiner.

US. Cl. X.R. 

